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(HuffmanCompression): classes utilizing Huffman compression.

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This commit is contained in:
morkt 2018-01-02 06:43:41 +04:00
parent 92a133fd52
commit 1a8b0d8b4a
2 changed files with 140 additions and 81 deletions
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81
ArcFormats/ArcCommon.cs
View File

@ -153,87 +153,6 @@ namespace GameRes.Formats
} }
} }
public class HuffmanDecoder
{
byte[] m_src;
byte[] m_dst;
ushort[] lhs = new ushort[512];
ushort[] rhs = new ushort[512];
ushort token = 256;
int m_input_pos;
int m_remaining;
int m_cached_bits;
int m_cache;
public HuffmanDecoder (byte[] src, int index, int length, byte[] dst)
{
m_src = src;
m_dst = dst;
m_input_pos = index;
m_remaining = length;
m_cached_bits = 0;
m_cache = 0;
}
public HuffmanDecoder (byte[] src, byte[] dst) : this (src, 0, src.Length, dst)
{
}
public byte[] Unpack ()
{
int dst = 0;
token = 256;
ushort v3 = CreateTree();
while (dst < m_dst.Length)
{
ushort symbol = v3;
while ( symbol >= 0x100u )
{
if ( 0 != GetBits (1) )
symbol = rhs[symbol];
else
symbol = lhs[symbol];
}
m_dst[dst++] = (byte)symbol;
}
return m_dst;
}
ushort CreateTree()
{
if ( 0 != GetBits (1) )
{
ushort v = token++;
lhs[v] = CreateTree();
rhs[v] = CreateTree();
return v;
}
else
{
return (ushort)GetBits (8);
}
}
uint GetBits (int n)
{
while (n > m_cached_bits)
{
if (0 == m_remaining)
throw new ApplicationException ("Invalid huffman-compressed stream");
int v = m_src[m_input_pos++];
--m_remaining;
m_cache = v | (m_cache << 8);
m_cached_bits += 8;
}
uint mask = (uint)m_cache;
m_cached_bits -= n;
m_cache &= ~(-1 << m_cached_bits);
return (uint)(((-1 << m_cached_bits) & mask) >> m_cached_bits);
}
}
/// <summary> /// <summary>
/// Create stream in TGA format from the given image pixels. /// Create stream in TGA format from the given image pixels.
/// </summary> /// </summary>

140
ArcFormats/HuffmanCompression.cs Normal file
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@ -0,0 +1,140 @@
//! \file HuffmanCompression.cs
//! \brief Huffman-compressed streams.
//
// C# implementation Copyright (C) 2014-2018 by morkt
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
using System.Collections.Generic;
using System.IO;
using GameRes.Formats;
namespace GameRes.Compression
{
public class HuffmanStream : PackedStream<HuffmanDecompressor>
{
public HuffmanStream (Stream input, bool leave_open = false) : base (input, leave_open)
{
}
}
public class HuffmanDecompressor : Decompressor
{
MsbBitStream m_input;
public override void Initialize (Stream input)
{
m_input = new MsbBitStream (input, true);
}
const int TreeSize = 512;
ushort[] lhs = new ushort[TreeSize];
ushort[] rhs = new ushort[TreeSize];
ushort m_token = 256;
protected override IEnumerator<int> Unpack ()
{
m_token = 256;
ushort root = CreateTree();
for (;;)
{
ushort symbol = root;
while (symbol >= 0x100)
{
int bit = m_input.GetBits (1);
if (-1 == bit)
yield break;
if (bit != 0)
symbol = rhs[symbol];
else
symbol = lhs[symbol];
}
m_buffer[m_pos++] = (byte)symbol;
if (0 == --m_length)
yield return m_pos;
}
}
ushort CreateTree ()
{
int bit = m_input.GetBits (1);
if (-1 == bit)
{
throw new EndOfStreamException ("Unexpected end of the Huffman-compressed stream.");
}
else if (bit != 0)
{
ushort v = m_token++;
if (v >= TreeSize)
throw new InvalidFormatException ("Invalid Huffman-compressed stream.");
lhs[v] = CreateTree();
rhs[v] = CreateTree();
return v;
}
else
{
return (ushort)m_input.GetBits (8);
}
}
#region IDisposable Members
bool m_disposed = false;
protected override void Dispose (bool disposing)
{
if (disposing && !m_disposed)
{
m_input.Dispose();
m_disposed = true;
}
}
#endregion
}
public class HuffmanDecoder
{
byte[] m_src;
byte[] m_dst;
int m_input_pos;
int m_remaining;
public HuffmanDecoder (byte[] src, int index, int length, byte[] dst)
{
m_src = src;
m_dst = dst;
m_input_pos = index;
m_remaining = length;
}
public HuffmanDecoder (byte[] src, byte[] dst) : this (src, 0, src.Length, dst)
{
}
public byte[] Unpack ()
{
using (var packed = new BinMemoryStream (m_src, m_input_pos, m_remaining))
using (var hstr = new HuffmanStream (packed))
{
hstr.Read (m_dst, 0, m_dst.Length);
return m_dst;
}
}
}
}